Hot-air engine.



J. R. SANDAGE.

HOT AIR ENGINE.

APPLIOATION FILED MAR. z5, 1912.

Patented Jan. 13, 1914.

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HOT AIR ENGINE.

APPLICATION FILED MAR. 25, 1912.

Patented Jan. 13, 1914.

2 SHEETS-SHEET 2 LLVZ felz'r .La 0 fia/z @y @ZM mdf@ 'UNITED STATE@ JACOB R. SANDAGE, OF OREGON, ILLINOIS, ASSIGNOR OF ONE-HALF T0 CHARLES W. WATSON, OF CHICAGO, ILLINOIS.

HOT-AIR ENGINE.

Specification of Letters Patent.

Application 1ed March 25, 1912.

Patented Jan. 13,1914.

Serial No. 686,109.

To all Lv/Loin it may concern Be it known that I, JACOB R. SANnAGn, a citizen of the United States, and a resident ot' Oregon, in the county of Ogle and State of illinois, have invented certain new and useful Improvements in Hotdir Engines; and do hereby declare that the following` is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

This invention relates to hot air or caloric engines and has for one of its objects to provide an engine of this type which is simple in construction and eifective in operation.

'lhe invention consists of the matteiis hereinafter described and more particularly pointed out in the appended claims.

.ln the accompanying drawings illustrating my invention: Figure l is a view representing a side elevation of a hot air engine constructed in accordance with my invention; Fig. 2 is a view representing a section in a plane indicated by the line 2 2 of Fig. l F 3 is a view representing a section on an enlarged scale in a plane indicated by the line of Fig. 1.

Referring to the drawings, A indicates a base or table-like stand for the engine as a whole, having a flat horizontal top (t provided with a centrally disposed opening through which extends and in which is rigidly secured an upright tubular casing B. which is preferably cylindric in form and made of `sheet metal, and supports above it the main or operative parts of the engine. #aid casing B is provided at its ends with top and bottom walls b, and extends substantially an equal distance above and below the vdat top n. of the stand A. is shown in the drawings, said stand A is made in two like parts or sections fi, ci?, the meeting or opposing edges of which are provided with mani-circular notches which register with each other to embrace the casing` B when the sections of the stand A. are assembled. rI`he sections fr. a2 are joined by bolts c3, a3, which serve to afford clamping engagement of the .said sections with the casing. (See Fig.

(l indicates a source of heat, in this instance, an alcohol lamp located within the casing B and seated on the bottom wall Z) thereof. An opening or doorway is made in l the cylindric wall of the said casing B below the tlat top a of the stand7 so that the lamp (l may be readily placed in. or removed from, the casing. The casing B constitutes the heatingI chamber of the engine.

l) indicates a base member for the main or operative parts of the engine, said base member having the form of a horizontal plate, which is supported above the heating chamber l?) by tubular spacing members (l (four of which are shown in the drawings) through which pass bolts (Z, rigidly connecting the said base member D to the upper wall 7/ of said heating chamber. Secured to the under side of the base member D in line with an axially arranged opening therein and extending downwardly therefrom into the casing B through the top wall Zi thereof, is the lower or heater part E of the expansion or displacer cylinder of the engine. Said lower or heater part E of the displacer cylinder is made of thin sheet metal. The lower end wall c of the heater part E of the said dis-placer cylinder is directlyv above and close to the lamp C. Secu red to and proj ect ing above the upper side of the base member D. in line with the heater part E of the displacer cylinder, is the upper or cooler part F of the said cylinder. which is made of cast metal and closed at the top by a top wall G, G, indicate laterally spaced, upwardly extending brackets secured to the upper side ot' the base member D, by bolts g, y, at each .side of the cooler part l? of the 'displacer cylinder. Said brackets G, G are provided ai their upper ends with bearings for a` horizontally arranged crank-shaft H extending between them and having rigidly secured to the outwardly extending ends thereof, outside ot' said bearings. `tty-wheels J, J. Lo-

cated within the displacer cylinder is a. hol- J low displacer piston K of a diameter .less than the inside diameter of the said displacer cylinder. Said displacer piston K is provided with an upwardly extending piston rod rigidliv connected to the upper end thereof, and projecting through a stuiiing box j in the top wall f of the cooler part F ot the said displacer cylinder. The upper end of the piston rod f is connected with a central crank pin 7L, on the crank-shaft H, by a pitman 71 whereby the said displacer piston K is reciprocated vertically within theI d isplacer cylinder.

L, L indicate two upright working cylinders open at their upper ends and secured, at opposite sides of the cooler part F of the displacer cylinder, to the upper side of the base member D, exterior to the brackets G, (if. Located within the working cylinders L, L and adapted to reciprocate vertically therein, are snugly .fitting working pistons Z, Z provided with connecting rods Z', Z', which are connected with the pistons by pivot pins Z2, Z2. The upper ends of said rods Z, Z are connected with crank pins on the outer faces of the fly wheel J, J. Ports or passages M, nl' in the base member D afford communication between the lower or bottom ends of the working cylinders L, L and the upper end of the cooler part F of the displacer cylinder, so that air within the displacer cylinder may readily pass back and forth between the working cylinders and the displacer cylinder during the reciprocation of the pistons therein. T he cooler part F of the displacer cylinder and the working cylin ders L, L, are all cast together in one single piece to gain cheapness of construction and accuracy in fitting. Laterally spaced grooyed pulleys N, )l are rigidly secured to the crank-shaft H inside of the brackets G, G and adapted to receive belts for the transmission of power.

The operation of the engine is as follows: The displacer piston K in the displacer cylinder being in its elevated position, namely, with its upper end practically illing the cooler part F of said displacer cylinder, the pistons Z, Z, in the working cylinders L, L will be in their intermediate posit-ions and moving upwardly. lVith the several pistons in the position above described, the main or principal part of t-he body of air in the displacer cylinder will be at the bottom of the same and betiween the bottom wall c of the heater part E of the displacer cylinder and the end of the piston K. The flame of the lamp C or other heating means acts directly on the end or bottom wall c of the heater part E of the said displacer cylinder and heats the said body of the air within the lower end thereof. Ars the said air is heated, it is caused to expand and passes around the cylindrical wall of the loosely fitting displacer piston K, through the ports or passages M, M and into the working cylinders L, L, to act directly upon the working pistons Z, Z therein to effect their outward or upward strokes. Both of said pistons Z, Z nove upwardly at t-he same time. This effects the rotation of t-he fly-wheels J, J, and the crank shaft H, with the result that the displacer piston K in the displacer cylinder is made to move downward. lhen the pistons Z, Z are moving downwardly and are midway of their downward strokes, the displacer piston K is at the limit of its downward stroke with its lower end practically Filling the lower end or bottom of the heater part. E of the displacer cylinder. (See Fig. 23). In this position of the piston K, its upper end is out of the cooler part F of the displacer cylinder, and the heated air previously in the lower part of the displacer cylinder will have passed into the space above the piston K. The walls of the cooler part i" of the displacer cylinder being exposed to the atmosphere and removed from the source of heat, will be much cooler than the heater part E, and as the heated air contracts or is lessened in volume as it parts kwith its heat, a lessened pressure or partial vacuum will be produced `in the upper part F of the displacer cylinder, and the air in the lworking cylinders L, L, below the pistons Z, Z will pass into the displacer cylinder through the passages El. M. The pistons Z, Z moving' downwardly through the power stored up in the fly-wheels, will tend to force the air beneath them tlirough the passages M, M into the upper part F of the said displacer cylinder. According to the extent to which the cooling of the air in the top of the displacer cylinder tends to create a partial racuum within the working cylinders L, L, the atmospheric pressure upon the exposed or upper ends of the pistons Z, Z, arising from such partial vacuum, will aid in drawing the said pistons downward. As the rotation of the fly-wheels J, J and the crank-shaft l-l, continues, and the reversal of moveli ent of the pistons Z, Z is being effected at the loiwer limits of their strokes, the displacer piston K is drawn upwardly, or makes its upward stroke. As the displacer piston K mores upwardly, it displaces the contracted or cool air in the cooler part F of the displacer cylinder, and causes the said air to pass downwardly around the cylindrical wall of the said piston K into the lower end or bottom of 'the heater part F of the displacer cylinder', to be again heated and expanded, as before. lt will be observed that the movement of the piston K displaces or shifts the principal part of the body of air within the displacer cylinder back and forth between the upper and lower ends of the same. Furthermore, the strokes of said displacer piston K are so timed, that it commences its upward and downward strokes when the working pistons Z, Z are midway of their upward and downward strokes and are exert-ing maximum turning effect on the crank-shaft, so that the air is being heated and expanded in the bottom of the displacer cylinder when the working pistons are exerting their greater effect on the crank-shaft in their upward movement, and the air in the top of the displacer cylinder is being cooled and contracted when the pistons are in position to exert t-he greatest turning moven'ient on the shaft in their downward strokes.

W hen the displacer piston is in its elevated position in the displacer cylinder, the body of the air in the lower part or bottom oit' the said cylinder, as it is heated and eX- panded, passes upwardly and also laterally or in a circumferential direction through the annular narrow space formed between the cylindrical wall ot the displacer piston and the wall ot' the displacer cylinder to the ports or passages M, M, ar 'anged at each side thereof, and diametrically opposite each other. The body oit heated air divides as it rises through said annular spacx and an equal part thereot enters ach ot' the working cylinders and acts on the pistons therein to etlfect their upward strokes, as above described. That part of the body of the heated air on the opposite sides ot the displacer piston and at opposite sides ot a vertical plane at right angles to a like plane passing through the pas ages leading to thel working cylinders, need only travel a circumferential distance equal to one-fourth ot the circumference ot' the said displacer cylinder or through an arc ot 90 degrees, in order to gain access to the said ports or passages. This is made possible by the ar 'angeinent ot' the said working cylinders on each side oit the ldisplacer cylinder and diametrically opposite each other, as above described.

l am aware that hot air engines ot' the same general construction have` been made, having one working cylinder in communication with one side only ot the displacer cylinder. ln such prior construction, that part tt the bcdy ot heated air in thc displacer cylinder at a point diametrically cppcsitc the port or passage leading to the working cylinder, must travel a circlunterential distance equal to one-halt the circum't'erence ot the d isplacer piston, or through an are ot Vi8() degrees, in order to gain access to the said port or passage. By reason ot the diametrical ar yangemeat ol the two working cylinders ot' the engine. illustrated, and ot the passages M. yi', by which the openings ot said passages into the displacer cylinder are equally spaced circum'ferentially ot the latter, l obtain uniform distribution ot pressure to the two working cylinders, and avoid the trictional resistance or retardation ot the tlow oil air trom the bottom oit the displacer cylinder to the working cylinders, such as occ irs in such engines as heretofore constructed, wherein the air flowing upwardly through the annular space between the walls ot the displacer cylinde' and the displacer piston makes its exit 'trom said annularspace at one point only in the circumlierence ot the displacer cylinder. and ontv a simili part. it any, ot the air in the part ot said annular space opposite the single passage leading to the working cylinder reaches the latter. it, is to be noted that the tre A and rapid passage ot the heated air to the working cylinders is o'l' great importance in an engine ot this kind because the engine must run at a very high rate ol speed in order to develop any conside lable amount ot' power. Careful tests with engines having a single working cylinder have demonstrated that the same are capable ot producing a very small amount ot power as compared with one having two working cylinders arranged as herein described, and that this is true regardless ot' the size ot the diameter oit' the working cylinder or cylinders. tn other words, it is found not to be possible to incr aise the power ot the engine by merely incraising the size or diameter oli' a single working cylinder. This arises trom the tact that the area of the working cylinder ot' a single cylinder engine must' have a delinite relation to that ot the displacing cylinder, in order to give a maximum degree ot power with a displacement cylinder ot a given capacity, and no advantage is gained by increasing the size ot such single working clv'linder. Vhen, however, two working cylinders aie used, the combined piston areas thereof may be made materially greater than the piston area ot a single. cylinder, with corresponding advantage in the amount ot' power dt-veloped; it being understood that the etlective action ot two cylinders is obtained by so ar 'anging the same and the passages connecting them with the displacement cylinder, that said passages open at equally spaced points circumterentially into the displacer cylinder, so as to facilitate and make unitorm the passage ot air to and trom the working cylinders, as liereinbefore stated. The compa 'ative inetiiciency ot' a single cylinder engine is also largely due to the tact that with a single working cylinder the passage leading to such cylinder must be made comparatively large. and the air yill pass through such large passage so freely that the 'workingl cylinder will become unduly heated, the air entering the displacer cylinder trom Athe working cylinder will not. be materially cooled. and the cooling ett'ect. in the top ot the displacer cyl,- inder will not be sutlicient to counte 'act the etii'ect ot the large body oit heated air delivered thereto from the working cylinder. lly using two cylinders, the passage to xach may be made o t the proper size to insure a substantial cooling ot the heated air before it passes 'trom the working cylinders back to the top of the displacer cylinder; it heilig understood that a certain degree ot cooling ot' the air in its passage to and 'trom the working cylinders` as well as the cooling ot the air in the top ot the (,lisplacer cylinderA is a Ytactor in obtaining ettective operation ot the engine. 'lhe opposite ar angement oit the two working cylinders also affords the advantage thatl the piston of both cylinders may act on crank pins located at opposite ends of a single crank sha't't.

n engine embracing the general features set forth may be variously constructed in its detain., and do not desire to be liniited to the speeiie features shown, except so tar as point-eel out in the aimenoed claims.

I claim as my invention:

l. in a hot air engine, a single displaeer cylinder', a one-part displacer piston therein, a plurality of upright working cylinders having' working pistons therein, said working cylinders being parallel to each other and to said single displacer cylinder, each working' cylinder being provided with a port or passage opening into the same displacer Cylinder at points equally spaced circumterentia ly of said displacer cylinder, and a horizontally arranged crank-shaftv supported above said cylinders having a central crank pi i 'for the displacer piston, the same crank-shaft being provided with a plurality ot Crank pins fer the working pistons, said displaeer piston being provided with a piston rod connected with said central crank pin and each ot said working pistons being provided witl a piston rod connected with one of the crank pins provided therefor; the crank pins with which the werking pistons are connected being so arranged with respect to the displacer piston crank pin, that said working pistons move simultaneously in the saine direction, and when in their midway position, the displacer piston is eithe the limit ot its outward or inward stroke.

In a hot air engine, a single displacer eylinde a one-part (disp aeer piston therein, two upright working cylinders having working pistcns therein, said working cylinders being parallel to each other and to said single displacer c vlinder and arranged at opposite sides of said single displacer cylinder, each of l`iid working cylinders being provided with a port or passage opening into the same displacer cylinder at the upper part thereot and at points dianietrieally opposite each other, and a horizontal crankshaft supported above said cylinders having a central crank pin. the same crank-shaft having a crank pin at each end thereof, said displacer piston being provided with a piston rod connected with said central crank pin and each ot said working pistons being provided with a piston rod Connected Wit-h one of the crank pins at the ends of the crank-shaft; the crank pins at the ends of the crank-shaft being so arranged with respect to the central crank pin thatsaid working pistons move simultaneously and when in their midway position and moving outward, the displaeer piston is at the limit of its outward stroke and when said Working pistons are in their midway position and moving inward, said displacer piston is at the limit. ot its inward stroke.

ln a hot air engine, an upright casing forming a lamp chamber, a support for said casing, a horizontally arranged base member t'or the operative parts ot the engine supported above said upright easing, a single displacer cylinder coniprisinga heater part and a cooler part, the former being secured to and extending from said base member into said upright easing, and the latter being secured to and projecting above the said base member, a displaeer piston in said displacer cylinder, two upright working cylinders having' working pistons therein mounted on said base member at opposite sides ot the displaeer cylinder and being parallel to each other and to said displacer cylinder, each of said working cylinders being provided with a port or passage opening int-o the cooler part of the saine displacer cylinder at points diainetrieally opposite each other, upright brackets mounted on said base member, and a horizontally arr; nged crank-shaft mounted in said brackets, said crank-shaft being provided with a Central crank pin and a crank pin at each end thereof, said displacer piston being provided with a piston rod connected with said central crank pin and each or' said working pistons being provided with a piston rod connected with one ot the crank pins at the ends of said crank-shaft.

In testimony, that I, claim the foregoing as my invention l atlix my signature in the presence of two witnesses, this day of March D. 1919.

JACOB R. SADAGE.

litnesses Gnonon R. YiLniNs, EUGENE C. VAUN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington. D. C. 

